I have been wet shaving with a DE since OCT 2013. It was the best decision I have made when it comes to shaving. I will answer your questions from the things that have worked for me. Just know that everything is different for everyone. Once you find something that works stick with it for a while and change little at a time.
1a: Brush/Stand. I purchased this set just to get my feet wet with DE shaving. I liked it, but it was cheap and lacked the adjustability that I wanted. I did keep the brush and stand. I always get a great lather with the brush and it is really soft. It is just as good as when I bought it. I shave everyday that I work.
1b: Handle. I started with the cheap handle that I listed above...it was not adjustable. I wanted an adjustable and bought a Merkur Futur. I love it.
1c: Blades. This is hard to recommend to someone. Get yourself one of many sample packs. Everyone likes different blades. Just try them all out. They are cheap. I chose based on the one that I cut my self with the least while giving be the best shave. Your probably going to cut yourself. It will go away with experience. I settled on the Astra Platinum blades. They are cheap on amazon with prime shipping.
1d: Soap. I am a huge fan of Proraso Shaving Cream. I have tried them all! But they are all I have tried. A tube last me a long time. My routine is to fill up an over sized coffee cup with hot water twice from my Keurig (No hot hot water in the morning due to my apartment) and poor it into the sink. Dunk my brush in the water and shake it off lightly. Put a dime sized blob of cream on the brush and make a lather in the over sized coffee cup.
1e: Pre/After Shave. I do not use any pre shave products. I just use the lather that i make and message it onto my face. Its really hot and frothy. I have tried all of Proraso's after shave products. The only one that I liked was the blue after shave balm. It didn't dry out my face like the others. Since then I have settled on Gillette Series Sensitive Skin After Shave Gel because it leaves my face feeling great, its cheap, and the better half loves the way it smells.
2: In my experience the razor (handle) makes a huge difference. I got to the point where I was not cutting myself at all with my first handle. Then I switched. I can shave quickly and comfortably because I found the setting that I really like (number 3 on the Futur). I also really like the way the blade is put into the handle. The top of the Futur pops off rather than having to unscrew the handle to change blades.
3: I answered this in section 1c.
4: I don't have too much info on this topic. I do know not to store your brush with the bristles in the air when it is wet (a stand will prevent this). Dry your razor off the best you can after use. Rinse a brush out thoroughly after use. I use a new blade each shave.
5: When I first started with a DE I watched a couple of Michael Freedberg's to get me started. Then I just did what was best for me.
The best thing that I can recommend for you is this. Figure out why you want to change to DE shaving. We already know its a better shave than using a cartridge. For me it was to be able to use a new razor blade for every shave and not spending a lot of money for those blades. I try to do this as cheaply as possibly. I had a big initial investment on the handle but it has since paid for itself by not buying cartridges. I found what works for me early on and stuck with it. I can have the same consistent shave everyday in 10 minutes because I have had the same routine for a while now.